The response of mouse B cells to hypoxia in vivo. a, WT mice exposed to 21% or 10% O2, were immunized with NP-KLH at day 1, then absolute spleen B cells enumerated at day 21. (Unpaired, two-sided Student's t-test). FO, (Unpaired, two-sided Mann-Whitney U-test). Gating in methods, mean ± s.e.m, circles represent individual mice (n=8 per group), data pooled from two experiments, results confirmed in a third. b, Serum NP-specific antibodies after NP-KLH immunization, (unpaired, two-sided Student's t-test). mean ± s.e.m, circles represent individual mice, (n=8 per group), data pooled from two experiments, confirmed in a third. *P < 0.05,**P < 0.01,***P < 0.001,**** P < 0.0001.